A vehicle control device for controlling a vehicle with a drive source, a friction transmission mechanism provided between the drive source and drive wheels and a fluid transmission mechanism provided between the friction transmission mechanism and the drive source includes a suppression unit configured to suppress a decrease of a speed ratio of the fluid transmission mechanism if the speed ratio becomes negative when the vehicle starts.

The present invention provides a shift control method implemented in a vehicle equipped with an automatic transmission for controlling an input shaft rotation speed to a target input shaft rotation speed during a shift. The method includes setting of a basic target synchronization rotation speed that is a basic target value of the input shaft rotation speed during the shift, and setting of a corrected target input shaft rotation speed as the target input shaft rotation speed when the shift is a downshift without a requirement for a driving force of the vehicle, The corrected target input shaft rotation speed is obtained by decreasingly correcting the basic target synchronization rotation speed. Further, a decreasing correction amount of the basic target synchronization rotation speed is set so as to become larger as a deceleration of the vehicle becomes larger.

A method for adapting a biting point pressure of a hydraulically actuated hybrid disengaging clutch arranged in a hybrid drive train of a motor vehicle between an internal combustion engine and an electric machine includes step by step implementation during driving of the motor vehicle via a plurality of selected engagement operations of the hybrid disengaging clutch with a manipulation of a rapid filling routine. Proceeding from an initially stored biting point pressure, a setting pressure, which is reduced relative to a subsequent rapid filling routine, is incrementally increased step by step. An actual value, which is set in each case for a test parameter, is detected until the actual value corresponds to a setpoint value. A change in the transmission of torque of the hybrid disengaging clutch is derivable via the actual value.

A method for operating a drive apparatus including an internal combustion engine and an electric engine. An output shaft of the drive apparatus can be operatively connected to the internal combustion engine by way of a shifting clutch and can be permanently operatively connected to the electric engine, so that the output shaft is disengaged from the internal combustion engine in a first shifting state of the shifting clutch and is engaged with it in a second shifting state.

Systems and methods for starting an engine of a hybrid vehicle are described. In one example, the method starts an engine according to vehicle conditions that are within a range that is defined by one or more thresholds. The thresholds may be adjusted based on a history of individual driving patterns.

The invention relates to a method for determining a bite point of a hybrid clutch in a hybrid vehicle. The hybrid clutch is actuated by a hydrostatic clutch actuator (12) and disconnects or connects an internal combustion engine (2) and an electric motor (3); the bite point is determined by slowly actuating the hybrid clutch (4) starting from a separating position of the hybrid clutch (4), this position being in the non-actuated state, with a defined torque reaction of the electric motor (3) being detected. The invention also relates to a method in which the quality of the bite point is improved, the duration of the bite point adaptation is essentially shortened, the bite point being adapted during the running of the internal combustion engine (2) and when the electric motor (3) is immobile and a torque reaction of the electric motor (3) is validated by the torque reaction of the internal combustion engine (2).

Systems and methods for improving operation of a hybrid vehicle are presented. In one example, an engine is couple to a transmission in response to a transmission upshift to reduce transmission output shaft torque disturbances.

A hybrid electric vehicle includes an engine and an electric machine, both capable of providing torque to transmission gearing. A clutch is disposed between the engine and the electric machine and is configured to selectively couple the engine to the electric machine. At times in which control of the amount of engine torque transmitted to the gearing is desirable, a controller is programmed to slip the clutch. If the controller is able to determine the amount of torque transmitted through the slipping clutch, the controller alters an output of the electric machine based upon the torque through the clutch. If, however, the controller is unable to determine the amount of torque transmitted through the slipping clutch, the controller alters the output of the electric machine based upon an acceleration of the electric machine.

A method of optimizing fuel economy and reduced noise and vibration levels in a vehicle includes one or more of the following steps: evaluating an engine speed and a speed of the vehicle, determining if the engine speed and the speed of the vehicle produces a noise level that causes a potential customer complaint, monitoring the noise level in the vehicle, calculating the engine operating condition that causes the noise level, determining if the noise level is above a threshold, adjusting an engine torque or a slip condition of a torque converter for optimal vehicle fuel economy if the noise level is at or below the threshold, and, if the noise level is above the threshold, adjusting the engine torque or the slip condition of the torque converter such that the noise level is at or below the threshold.

A method for operating a powertrain of a hybrid vehicle is provided. The method includes outputting via a controller an engine speed command that is based on a predicted impeller speed of a torque converter and corresponds to the accelerator tip-in to output a torque from the engine to wheels of the vehicle in response to detection of an accelerator pedal tip-in greater than a predetermined threshold. The method may also include accessing a history of impeller speed outputs of the hybrid vehicle to obtain the predicted impeller speed. The engine speed command may set engine speed substantially equal to or greater than the predicted impeller speed. The predetermined threshold may be based on a driver requested torque output of the wheels in which torque from the torque converter to the wheels results in saturation.